Primary follicular lymphoma of the gastrointestinal tract.

BACKGROUND: Follicular lymphoma (FL), a common nodal lymphoma, is rare in the gastrointestinal (GI) tract. We report our experience with primary FL of the GI tract.

METHODS: The surgical pathology computer files at the Massachusetts General Hospital were searched for cases of FL involving the GI tract. Patients were included if on staging, the major site of disease was the GI tract. Thirty-nine cases were identified. Clinical data were collected from electronic medical records.

RESULTS: The 27 women and 12 men ranged in age from 29 to 79 years (median, 59 y). Thirty tumors involved the small bowel (19 the duodenum); 8 involved the colon; and 1 involved the stomach. Eight of 10 tumors that were resected involved the small bowel (jejunum and/or ileum without duodenum) of which 5 presented with intestinal obstruction. All tumors were grade 1 or 2. Immunostains showed consistent expression of CD20 (100%), CD10 (97%), and Bcl-2 (97%). Among the 34 cases with Ann Arbor staging information, 22 were stage I, 10 were stage II, and 2 were (6%) stage IV. Of 36 cases with follow-up (median, 4.5 y), 27 patients are alive without disease, 7 are alive with disease, and 2 died of other causes. No lymphoma-related deaths were recorded.

CONCLUSIONS: Primary FL of the GI tract occurs most often in middle-aged adults with a 2:1 female preponderance. The most frequent site of involvement is the duodenum, followed by the ileum and colon. Distal small bowel involvement is more likely to present as bowel obstruction requiring resection. The disease is localized in the bowel and regional lymph nodes in the vast majority of cases. The prognosis is favorable even when the disease is disseminated.